Medication management of pain is part of the multidisciplinary approach to treatment and is designed to enable the patient to resume normal daily activities. Because the pain persists, extended drug treatment becomes necessary. Even though several different drugs are used in managing chronic pain, the effectiveness of most medications has not been demonstrated by controlled clinical trials. The physician always considers these issues along with patient-specific factors, including other medical problems and side effects of medications, and federal and state regulatory requirements, when selecting the most appropriate drug treatment for a patient with chronic pain.In a survey conducted in November of 1998, when asked to rate the effectiveness of the pain medicine they had tried, chronic pain sufferers gave opioid (narcotic) drugs, the highest score. Approximately half of the patients who had taken narcotics reported concerns about addictions – fears that experts believe are often exaggerated or misplaced. When it comes to medication management, every chronic pain patient should ask themselves if they have any fears or concerns about pain medications. Many people are reluctant to take pain medications because of concerns about side effects. Others are worried they will become “hooked” or addicted. Contrary to the patient opinion’s, most physicians consider chronic administration of narcotics as detrimental to the patient’s health and also causes addiction. Several medications are available for treating chronic pain of varying intensity apart from narcotics:
1. Most commonly used drugs are known as non-steroidal anti-inflammatory drugs (NSAIDS). These are used mainly for mild to moderate pain. These are available over-the-counter, as well as with prescription. These include aspirin, Tylenol, ibuprofen, and numerous other drugs such as Lodine ®, Daypro ®, Celebrex ®, Vioxx ® and, Bextra ®.
2. The second group of drugs used is narcotics. Generally narcotics are indicated only for severe pain. There are numerous types of narcotics available in the market which range from mild drugs such as Darvocet ®, Darvon and Ultram® to moderately potent drugs such as Talwin ®, Stadol ®, Hydrocodone (most commonly known as Lortab ®, Lorcet ®, Vicodin®, etc), and in the high range, the most potent drugs are Oxycodone (also known as OxyContin ®, Percodan ® , Percocet ® , or Tylox), Demerol, Morphine, and Methadone.
3. Other drugs used in managing chronic pain include muscle relaxants, medications used for depression and anxiety, medications used in convulsions, and medications given into the epidural space or spinal cord which include steroids and morphine.
4. Tylenol or acetaminophen is useful for mild pain. However, Tylenol does not have anti-inflammatory activity whereas others do. It is believed to reduce pain by inhibiting the generation of peripheral pain impulses and transmission of central nociceptive impulses. Tylenol is a relatively safe drug because it causes few side effects. However, it has the potential to cause liver toxicity, especially in people who consume more than three alcoholic drinks per day or who have liver dysfunction, or who take more than six tablets of Tylenol a day.
Non-steroidal anti-inflammatory drugs have pain relieving effects similar to Tylenol and at the same time, have anti-inflammatory effects which reduce the inflammation and also reduce the fever. These drugs work by inhibiting cyclooxygenase (more formally known as Cox Pathways) by inhibiting the production of prostaglandins. Cox pathways are further divided into two types: Cox I, which is present in most tissues and Cox II, which is induced by various substances in the body including endotoxins, so-called mitogens, and cytokines. The majority of non-steroidal anti-inflammatory drugs which are currently on the market and used in the treatment of arthritis or pain, non-selectively inhibit both Cox I and Cox II. Of course, some of the drugs work more on Cox II than Cox I.
In 1998 Celebrex ® (a selective Cox II inhibitor) was introduced, followed in 1999 by Vioxx ® (also a selective Cox II inhibitor) and Bextra ® in 2001. While Cox II inhibitors may be safer, the effectiveness either is equal or better. Non-steroidal anti-inflammatory agents are the most frequently prescribed medications for chronic pain. Low doses, such as Ibuprofen 400 mg, three times a day, provide pain relief, whereas higher doses, such as Ibuprofen 800 mg, three times a day, are needed for full anti-inflammatory action. However, it is not known whether there is any type of inflammation present in chronic pain at all. In general, evidence shows that these agents work better than sugar pills.
Because prostaglandins work to maintain gastrointestinal tract integrity, normal kidney blood flow, and balance among various substances in the body, non-steroidal anti-inflammatory drugs have the potential to cause important adverse events, especially among the elderly. NSAIDS cause significant gastrointestinal effects with stomach upset and occasional ulceration, along with damage to the kidney and kidney failure, especially in patients with compromised kidney function. They may also cause liver disease, and occasionally cause sodium and fluid retention, especially in patients with heart failure. NSAIDS may also result in increase blood pressure in patients with coronary artery disease, and, finally, they may cause increased levels of potassium in diabetic patients.
Ultram® is a mixed agent functioning centrally on the brain cells, which is effective in the management of moderate to severe pain. It has been shown in studies to be equivalent to the effects produced by Tylenol #3. It presents with two types of actions, one is a narcotic type of action and the other one is similar to antidepressant medications. Even though it is considered to have a low potential for abuse or dependence, it is not advised to be used in patients with a history of abuse or drug dependence.
Pure narcotic agents produce pain relief by binding to opioid receptors at spinal and supraspinal sites. Narcotic analgesics mainly are used to treat severe pain. Their duration of action ranges from three to six hours with Codeine or Oxycodone, to three days with long-acting drugs like Fentanyl patches. Many physicians are reluctant to recommend extended use of narcotic medications for chronic non-cancer pain due to the safety and addiction potential. Various types of narcotic agents include Codeine (Tylenol #2, #3, and #4), Percodan ®, Percocet ®, Tylox ®, OxyContin ®, Oxycodone, Morphine, Hydromorphone (Dilaudid®), Propoxyphene (Darvocet® or Darvon®), Hydrocodone (Lortab ®, Lorcet ®, Zydone ®, Vicoprofen ®, and Vicodin®) and Fentanyl (Duragesic ® patches).
Muscle relaxants have a limited role in the treatment of chronic pain because muscle spasm is unlikely to be the source of chronic pain even though numerous patients complain of this. In addition, these drugs produce undesirable side effects which include drowsiness with long-term use. In addition, they have not been shown to be effective in chronic pain management in various studies.
Antidepressants are useful in patients with chronic pain with or without clinical depression. In patients with depression, higher doses are used to counteract depression and also help pain. However, antidepressants have been shown to be helpful in managing chronic pain, especially pain coming from damage to the nerve endings.
Anticonvulsants or medications used in epilepsy and seizures are also useful in chronic pain management, especially with nerve injury or damage.
Medication management is an extremely important aspect of pain management. Medication management of chronic pain always poses a challenge to primary care physicians. In selective pain medications, the physician must consider the intensity and duration of chronic pain, as well as a number of other factors, including patients age, other medical problems, other medications, and serious side effects, as well as potential for drug abuse. Regardless of any type of management, medication should be part of the multidisciplinary approach that should include medication management in conjunction with other treatments. The Federation of State Medical Boards of the United States, Inc has developed model guidelines for the use of controlled substances for the treatment of pain. These guidelines were developed from a working group, which included members of the American Academy of Pain Medicine, American Pain Society, American Society of Law, Medicine, and Ethics, Pain and Policy Studies Group, University of Wisconsin, and various State Boards. These are only model guidelines and have not been implemented by all State Medical Boards. Salient features of these guidelines are:
1. Comprehensive evaluation of the patient
2. Written treatment plan
3. Informed consent and agreement for treatment including controlled substances agreement
4. Periodic review
5. Appropriate consultations as necessary
6. Maintain medical records
7. Compliance with controlled substances loss and regulation